Abstract: Japanese scientist Shimon Sakaguchi, together with American scientists Mary E. Brunkow and Fred Ramsdell, were jointly awarded the 2025 Nobel Prize in Physiology or Medicine for their pioneering discoveries in the field of peripheral immune tolerance. This review summarizes the research on immune tolerance which have already been award by Nobel Prize several times, and the history of development and function of regulatory T cells. The therapeutic applications of Treg-based therapy in diseases are discussed too, offering the perspectives on precise immunomodulation.